Steam and hot-water boiler



e 1949. H. A. GIROUARD STEAM AND HOT WATER BOILER 3 Sheets-Sheet 1 FiledOct. 31, 1946 Q I Inventor 1%1'4/6 ,4 fizfloaazui Attorneys m- 1949- H.A. GIROUARD 2,461,051

-STEAM AND HOT WATER BOILER Filed Oct. 51, 1946 r 4 5 Shecs-Sheet 2 lllllllll Attorn'eyg Feb. 8, 1949.

H. A. GIROUARD STEAM AND HOT WATER BOILER s Shets-Sheet 3' Filed Oct.31, 1946 Attorneys Patented Feb. 8, 1949 2,461,051 STEAM AND HOT-WATERBOILER Herv Adelard Girouard, Montreal, Quebec,

Canad Application October 31, 1946, Serial No. 706,887

5 Claims. 1

. The present invention relates to heating devices and, moreparticularly, a boiler for steam or hot water.

The main object of the invention resides in the provision of a device ofthe character described which operates at high efiiciency.

Another object is the provision of such a device which is highlyversatile in use.

A further object concerns a boiler of the character described adapted tooperate at a high degree of economy.

Still another object contemplates a hot water or steam boiler in whichconvection losses are reduced to a minimum.

A still further object envisages a. boiler relatively inexpensive andeasy to construct.

Other objects and advantages of the invention will become apparent, orbe pointed out further, during the description to follow.

As an example, and for purposes of illustration only, an embodiment ofthe invention is shown in the annexed drawings wherein:

Fig. 1 is a top plan view of a boiler according to the invention;

Fig. 2a is a vertical section through the upper portion of the boiler;

Fig. 2b is a vertical section through the lower portion of said boilerand complementary to Fig. 2a;

Fig. 3 is a partial elevation of taken on line 3-3 of Fig. 2a.;

Fig. 4 is a horizontal half section taken on line 44 of Fig. 2a;

Fig. 5 is a similar view taken on Line 5-5 of Fig. 2a; and

Fig. 6 is yet another similar view taken on line 66 of Fig. 2b.

Referring to the drawings, wherein similar reference charactersrepresent corresponding parts throughout, the reference letterdesignates the outer casing of the device, which casing encloses theboiler itself, water jacket, fiues and other elements associated withsaid boiler. A base B terminates the bottom of said casing, which baseserves as an ash pit when burning solid fuel, or a burner compartmentwhen liquid or gaseous fuel is used. The trap door Ill serves to tendthe fire or service the burner.

Disposed inside the casing, and spaced concentrically therefrom, thereis provided the boiler proper which consists of a cylindrical wall l5,;defining a combustion chamber C, and a water Jacket therearound. Saidjacket is formed by the bottom wall l1 and the double wall is spacedfrom the casting l and extending upwardly for the outer casing cult iscompleted by a portion of the boiler height; furthermore, the upper partof said jacket is constituted of double plates and a dome to bedescribed later on.

As shown to advantage in Fig. 2b, the outer wall l8 of the jacket isdepressed to form an annular cavity IS, the wall 20 of which accordinglylies closer to [5 to form therewith a constriction in the jacket,approximately adjacent to the point of the combustion chamber where thehighest temperature prevails.

The upper edge 2| of the outer jacket wall I8 extends very slightlyabove the cavity I9 to form a flange, said flange receiving the lowerextremity of a double wall comprising the upper part of the jacket. Thisdouble wall consists of concentric cylinders 23 and 24 spaced to form adead-air space 25 therebetween, for heat insulating purposes. Saiddouble wall is domeshaped at the top, and apertured to receive theoutlet header 26 welded or otherwise secured to the inner cylinder 23,as shown in Fig. 2a; the outer cylinder 24 terminates short of the saidheader to accommodate a collar 21 to which a casing cover is attached.

The inner wall 15 of the jacket, defining also the combustion chamber C,is provided at its upper edge with a marginal flange 39 having aperipheral upstanding rim 3|, said rim retaining a dome 32 restingthereagainst on the flange 30. To thesummit of said dome a flue pipe 33is Welded and which extends upwardly through the jacket and header 26,where it issues through the packing gland 35. The water circulatingcirthe addition of a water inlet 35 disposed at the bottom of thejacket, in the outer wall I 8; thus, water enters 36, rises in thejacket and the dome until it comes out of the boiler through the outletpipe '31 connected to the header 26.

The circuit of the combustion gases forms, in reality, the importantcharacteristic of the invention; said circuit is arranged to completethe longest possible travel of the gases between their inception andtheir exhaust to a chimney.

The first portion of this travel is the obvious upward movement from thesource of heat to the dome of the combustion chamber where furtherupward movement through the pipe 33 is normally blocked-for reasons tobe explained later on. From the dome, the next portion of the gasestravel is a downward movement through .a multiplicity of pipes disposedbetween the flange 30 and the wall 4| of the cavity I 9 and.

effecting communication between the dome'of .the combustion chamber andsaid cavity 19 in the outer side of the water jacket, as previouslydescribed. In order that the gases circulating in said pipes All heforced to scrub the side of said pipe, internally, there is placed ineach tube or pipe a twisted narrow strip of metal 42 the edges of whichcontact the inside walls of the pipes and form, in effect, a screwthread imparting to the gases a rotary movement.

The combustion gases discharged in the cavity 19, and enclosed betweensaid cavity and the outer casing have a natural tendency to escapeupwardly between the outer wall 24 of the water jacket and said casing Oto collect at the top'oi said casing. The gases are then exhausted to achimney through a flue pipe 45 connected to the casing cover 23 andtherefrom to the chimney pipe 46.

For by-passing purposes, as for instance when starting a fire in theboiler, a short connection 41 between the ducts 33 and 46 is provided sothat the hot gases rising in 33 may escape directly to the chimney.When, however, the boiler has been properly heated and a clean fireobtained, the butterfly-valve 59 maybe closed by means of the outerhandle to interrupt communication between 33 and id: obviously, in thatcase, the gases will have to follow the travel previously given to thepipe as and around the water jacket.

So far described, the boiler is perfectly operable to heat water in anefilcient manner and to conduct the combustion gases to a chimneyassuming, however, that the air of combustion is drawn through the doorH3 or suitable regulatable opening therein. In order to increase furtherthe efficiency of the device, and to reclaim, so to speak, a greaterportion of the heat contained in the combustion gases, heat-exchangingmeans in the casings proper are provided and will be presentlydescribed. 1

Said heat exchanging means consists of a network of tubes disposed invertical and spaced parallel relation, said tubes 59 extending insidethe casing between the same and the outer wall 24 of the water jacket.Furthermore, the said tubes open at their lower end near the bottom ofsaid Water jacket immediately below the cavity l9. ,At their upper endthey terminate just short of the casing cover 28 and are provided withelbows 51 through which the upper end of the tubes open to theatmosphere outside the casing. As shown to advantage in Fig. 2b, thelower ends of the tubes 50 extend through an annular plate 52 closingthe bottom of cavity [9 between the wall and casing proper 0. Purpose ofthis arrangement is to form a barrier between said cavity [9 and theunderside of the boiler proper which communicates with the combustionchamber at the bottom thereof. The tubes :50 opening below the barrier52, therefore operate to admit below said barrier the air necessary forcombustion purposes.

Inasmuch as said air of combustion is carried downwardly in the pipe 40,in counter-current to the hot combustion gases circulating around thetubes =58 on their way to the chimney, a large amount of the heat ofsaid gases will be transferred by conduction through the tubes to theaircirculating therein, which air of combustion will be effectively heatedbefore being admitted to the combustion chamber. The net result of thisarrangement is .to provide an inner lining in. the casing whicheffectively cools the same and, thereby, avoids a great loss of heat byconvection on the outside of said casing.

other refinements of the boiler according to-the invention may consistof a water level gauge 55 whenever said boiler is to be used for steamheating, a steam pressure gauge 56 in the outlet header 26, as well asspy glass Bil disposed at the extreme top of the duct 33 for visuallyinspecting the flame inside the furnace whenever desired.

Under certain peculiar conditions, it may happen that condensationoccurs on the outer surface of the pipe 58, especially when starting afire in the boiler, in which case water may drip in the cavity l9 andaccumulate over the annular plate 52; in order to drain this water afaucet or cook 65 is provided in one side of the casing immediatelyabove 52 for removing accumulation of condensation water.

' Finally, for facility in installation the boiler may be mounted onadjustable legs 10 which are directly attached to the base of the waterjacket, as shown clearly in Fig. 219.

From the foregoing it should be evident that the present invention is anadvance of the art in that it provides for a boiler which is easilyadaptable to hot water or steam heating, which boiler is very compactand quite-eflicient for burning any fuel whatever in a most economicalmanner. More particularly, it is emphasized that the reverse flow ofcombustion gases circulating in a direction opposed to the naturalcurrent of water being heated, result in .a most complete transfer ofthe heating energy, the heat exchanging net work of the outer partfurther avoiding the convection losses which are normally present inboilers having heated walls in directxcontact with atmospheric air.Thereforaclumsy and costly insulating jackets are unnecessary and theirabsence provide for amore compact and neat device.

It must be understood that various changes as to the shape, size andarrangement of parts may be resorted to without departing'from thespirit of the invention orthe scope of the subjoined claims.

Having thus described my invention, I claim:

1. A broiler of the character described, comprising a combustionchamber, a water .jacket surrounding said chamber, a dome at the top ofthe chamber, flue pipes extending downwardly inside the jacket fromthe-dome margin to an intermediate peripheral cavity on the outside ofthe jacket, a casing spaced from the jacket and surrounding the same toform a concentric smoke fine, a chimney flue connected to the top ofsaid casing, an annular ring at, the'bottom of the jacket cavity toclose the space betweenthejacket and casing, and a plurality of closely,spaced parallel tubes opening near the top-of the casing and extendingdownwardly inside the :same .and through the ring for admitting-.combusticn .air thereunder.

2. In a boiler as claimed in claim 1, twisted fiat narow strips insertedinside the flueipipes for imparting a rotating action to the combustiongases circulating therein.

3. In a boiler as claimed in claim 1,.a duct connecting the top of thedome to the chimney fine, and valve means in said duct for interruptingcirculation therein.

4. In a boiler as claimed in claim 1, means at the bottom-of the jacketcavity for draining condensation water accumulating therein.

5. In a boiler, a combustion chamber, a water jacket surrounding saidchamber havin'g'a perimetric recess intermediate the length thereof,flue pipes extending longitudinally through said jacket in communication"at one end 'withsaid chamberand at the other end with said recess, acasing spacedlyenclosin'g said jacket and :cham- 5 6 her to form aconcentric smoke flue, a ring plate between the casing and the jacketclosing the I REFERENCES CITED space therebetween adjacent the recess,and a, The following references are of record in the plurality ofclosely spaced parallel tubes open to fi Of this Patent! the atrnospherenear one end of the casing and 5 UNITED STATES PATENTS extendmgl0ng1tud1na1ly made the same and outside the water jacket andpenetrating through the Number N D said ring plate for admittingpreheated air of com- 171557 Colllgnon J n 25, 1376 b stion to saichamber, 1, Klu h Mar. 21, 1899 HERVE ADELARD GIRQUARD 10 3 Tlumble Oct.19, 1920

